Class: God::Hub

Inherits:
Object
  • Object
show all
Defined in:
lib/god/hub.rb

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.directory ⇒ Object

directory to hold conditions and their corresponding metric

key: condition
val: metric



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# File 'lib/god/hub.rb', line 8

def directory
  @directory
end

Class Method Details

.attach(condition, metric) ⇒ Object 



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# File 'lib/god/hub.rb', line 13

def self.attach(condition, metric)
  # add the condition to the directory
  self.directory[condition] = metric
  
  # schedule poll condition
  # register event condition
  if condition.kind_of?(PollCondition)
    Timer.get.schedule(condition, 0)
  else
    condition.register
  end
end

.detach(condition) ⇒ Object 



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# File 'lib/god/hub.rb', line 26

def self.detach(condition)
  # remove the condition from the directory
  self.directory.delete(condition)
  
  # unschedule any pending polls
  Timer.get.unschedule(condition)
  
  # deregister event condition
  if condition.kind_of?(EventCondition)
    condition.deregister
  end
end

.handle_event(condition) ⇒ Object 



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# File 'lib/god/hub.rb', line 84

def self.handle_event(condition)
  Thread.new do
    metric = self.directory[condition]
    watch = metric.watch
    
    watch.mutex.synchronize do
      msg = watch.name + ' ' + condition.class.name + " [true] " + metric.destination.inspect
      Syslog.debug(msg)
      puts msg
      
      dest = metric.destination[true]
      watch.move(dest)
    end
  end
end

.handle_poll(condition) ⇒ Object 



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# File 'lib/god/hub.rb', line 47

def self.handle_poll(condition)
  Thread.new do
    begin
      metric = self.directory[condition]
      
      # it's possible that the timer will trigger an event before it can be cleared
      # by an exiting metric, in which case it should be ignored
      return if metric.nil?
      
      watch = metric.watch
    
      watch.mutex.synchronize do
        result = condition.test
      
        msg = watch.name + ' ' + condition.class.name + " [#{result}] " + metric.destination.inspect
        Syslog.debug(msg)
        puts msg
      
        condition.after
      
        dest = metric.destination[result]
        if dest
          watch.move(dest)
        else
          # reschedule
          Timer.get.schedule(condition)
        end
      end
    rescue => e
      message = format("Unhandled exception (%s): %s\n%s",
                       e.class, e.message, e.backtrace.join("\n"))
      Syslog.crit message
      abort message
    end
  end
end

.trigger(condition) ⇒ Object 



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# File 'lib/god/hub.rb', line 39

def self.trigger(condition)
  if condition.kind_of?(PollCondition)
    self.handle_poll(condition)
  elsif condition.kind_of?(EventCondition)
    self.handle_event(condition)
  end
end